Painting Tumors

When treating cancer with surgery, it's crucial that every bit of the disease has been removed; but spotting cancer cells left behind after a tumor has been removed is difficult. Now, however, researchers at Seattle's Fred Hutchinson Cancer Research Center have created a molecular "paint" that coats cancer cells so doctors can see the wayward ones that they might otherwise miss.

The paint is a blend of chlorotoxin derived from the scorpion (nonpoisonous to humans) and a fluorescent molecule that emits near-infrared light. The scorpion-derived peptide homes in on the cancer cells and binds to them, bypassing healthy...